One known multipurpose weapon is a standard assault rifle equipped with a grenade launcher barrel mounted thereon, and is described in German patent DE 32 02 806 C2. That multipurpose weapon includes a conventional rapid-fire weapon having a grip piece, a conventional trigger arrangement and a relatively short grenade launcher barrel mounted to the distal end of the shaft portion of the rifle barrel. The grenade launcher barrel is equipped with a separate breech block and trigger assembly. The rear end of the grenade launcher barrel can be swung downward to remove a spent cartridge and to reload the grenade launcher. Adjacent the rear end of grenade launcher barrel is a grooved outer surface which functions as the front shaft of the combined weapon. Operating elements in the form of a locking slide and a trigger are located above the grooved outer surface. Those operating elements are operable by one hand of the user gripping the grooved outer surface. The other hand of the user is used to hold the grip of the assault rifle and to operate the trigger, safety device, and other operating elements of the assault weapon.
This arrangement provides suboptimal orientation of recoil impact forces, particularly when the grenade launcher is utilized. The position of the normal-caliber assault rifle barrel with respect to the shoulder support of the weapon is arranged such that the recoil force is transferred in a desirable manner to the shoulder of the user. The barrel of the grenade launcher, which produces greater recoil, is positioned underneath the barrel of the assault rifle and is therefore suboptimally positioned with respect to the shoulder support. The recoil generated by the operation of the grenade launcher is therefore transferred in a less-than-optimal fashion to the shoulder support and can affect the accuracy of aiming the grenade launcher and firing.
The loading process of the grenade launcher barrel is also rather problematic. A cartridge introduced into the downward tilted (and therefore obliquely positioned) barrel has the tendency to slip out of the cartridge chamber before the user can counter-rotate the barrel back to the operating position. If the user attempts to hold the cartridge in the barrel while pivoting the barrel upward, his fingers are susceptible to being pinched between the breech block and the barrel of the grenade launcher.
Furthermore, a second magazine is often attached beside the magazine in use with an isolating band or the like in order to facilitate a faster magazine change for the assault rifle. The second magazine necessarily extends downward and hinders the reloading of the grenade launcher barrel.
With this arrangement the grenade-launching barrel with its breech is fixedly mounted to the assault rifle and cannot and should not be removed. In addition, due to its high recoil, the grenade-launching system could not be fired with the stock of the assault rifle removed without injuring the user.
Another known multi-purpose rifle is described in European patent application 0 294 346. This multipurpose rifle includes a repeating shotgun and a submachine gun which are also combined to form an integrated multi-purpose rifle. The large-caliber system is adapted solely for firing shot, rubber projectiles or the like and is suitable for firing non-spin-stabilized projectiles only at very short range. The submachine gun portion is intended for longer range fire, however, the cartridges used for the ammunition have low ballistic efficiency. One of the disadvantages of this system is that the shotgun and submachine gun portions of the weapon are substantially inseparable.
A further multi-purpose rifle known to the applicant includes a simple repeating rifle, e.g. the kind used as a military rifle during World War I, into which a submachine-gun system is integrated. Once again, a disadvantage of this weapon is that the submachine-gun portion cannot be disassembled and reassembled quickly and easily by a user. In particular, each time the submachine gun portion is reassembled it has to be laboriously aligned with the sight of the repeating-rifle portion. Moreover, the infantry rifle portion has a caliber on the order of only approximately 20 mm and thus is not suitable for large-caliber cartridges.
Although past efforts to combine rifle barrels of different calibers generally have produced unsatisfactory results, the need for such combination weapons exists. For example, large-caliber rifle cartridges that deploy so called "intelligent ammunition" have been developed. As used herein, "intelligent ammunition" is intended to mean a type of ammunition which, possibly in cooperation with a guidance system mounted on the weapon, automatically and independently locks onto a target, thereby providing considerably improved targeting accuracy. The combination of a weapon capable of firing such intelligent ammunition with an assault rifle provides a resulting weapon that is very versatile and very powerful.
The projectiles of intelligent ammunition typically have an initial velocity that is much higher than that of the cartridges for the grenade launcher described above. It is well known that the muzzle energy achievable in a hand-held firearm is limited by the recoil impulse that the user can withstand. This impulse is reduced when its duration is lengthened such as by means of the recoil of a breech block after the firing. In order not to exceed the impulse tolerance limit of average users, the firing of large-caliber intelligent ammunition cartridges requires a weapon with a breech block, such as a self-loading rifle.
Because of the good targeting accuracy and high effectiveness of hit performance (typically within 1000 meters) of the intelligent ammunition described above, it is desirable to equip at least one or two soldiers in an infantry unit with large-caliber self-loading rifles capable of firing intelligent ammunition even though the rifle and the ammunition tend to be heavy. Nevertheless, due to the increased weight of the ammunition and its resultant high recoil, it is not practical to operate such a self-loading rifle in a continuous-firing mode. The firing strength of an infantry unit is seriously weakened if two soldiers in the group are not capable of maintaining continuous firing. It is possible to ameliorate this problem by equipping a soldier carrying a large-caliber rifle with a pistol. Such an approach is not satisfactory, however, since the soldier is required to carry a second weapon which must be separately handled, and requires handling of corresponding cartridges. Likewise, it is not recommended to equip such a soldier with a submachine gun, or an assault weapon since such auxiliary equipment can be overly heavy and cumbersome as to severely restrict the movement of the soldier.